I recommend getting Dual Chargers if you can afford it, they are useful now and they will only become more useful in the future as more higher amperage destination chargers become available.
Well, I find it the opposite. There were two trips I took early on when we had the car when there were no Superchargers in this part of the country where there was an 80A HPWC available that I used at 40A, and it was really slow. Now that the Superchargers are here, those trips are easy, and I don’t see a need for dual chargers in the future.
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Heading east from Bend, its 318 miles to the Supercharger in Boise, ID. There's an older Tesla branded J1772 charging station behind the Harney County Chamber of Commerce in Burns. It runs at 208v, 70 amps. Over Christmas we used it to springboard us to Boise, charging for 2 hours in the evening while we ate dinner, then spent the night in a nearby motel plugged into a 120v wall plug (mainly to keep the battery warm), and then plugged it in for another 2 hours in the morning while we got ready and ate breakfast.
I live in Boise, and I’ve looked at that route to/from Bend. Since I don’t have dual chargers, that high amp charger in Burns wouldn’t benefit me anyway, but the route I figured out was this. Instead of going through Burns and Ontario, it looks like you can go all the way through John Day to Baker City to the Supercharger (if you have an 85), and then easily get to Boise. It is about 40 miles farther, but there’s no slow charging.